The invention relates to a drive device for an electrical switching device, in particular for a high voltage switch, according to the preamble of claim 1. Such a drive device is known, for example, from DE 9109812.
The known device has the disadvantage that in an operable state no influence can be exerted on the characteristics of the spring of the energy storage device and thus the operating behavior of the energy storage device. In particular, a housing containing the insulating fluid must be opened to influence the spring which first requires an elaborate suctioning-off of the insulating fluid and then, after any maintenance of the spring, a re-filling to restore a ready-to-use state.
Accordingly, it is an object of the present invention to improve a device of the type mentioned above to avoid the aforementioned disadvantages and, in particular, enable the exertion of influence on the operating behavior of the energy storage device without having to open the housing.
According to the invention, this object is achieved by the drive device mentioned above by providing an adjustment device which can be actuated from the exterior of the housing, by means of which a position of the stop in the housing can be adjusted along an axis. This advantageously makes it possible to influence the mechanical energy stored in the spring in the tensioned state by varying the position of the stop. By using the adjustment device according to the invention, especially advantageously, the position of the stop used for tensioning the spring can be adjusted by an actuation of the adjustment device which takes place on the exterior of the housing so that no evacuation of the housing or a refilling with insulating fluid, in particular insulating gas, is required after adjustment. Rather, the housing can be left unopened and filled with insulating fluid for the entire adjustment operation, so that the drive device according to the invention is always ready for operation and is nevertheless flexibly adjustable with regard to the energy stored in the spring. This makes it possible, in particular, to adjust the spring energy and thus the operating behavior of the energy storage device of the switching device in the field during operation of the drive device.
Applying the principle according to the invention, particularly advantageously, a simple adaptation of the operating behavior, in particular of the (switching) behavior of switching devices, in particular of the switching times can take place, which, in addition to the mass system of the chain of action (spring, drive rod(s), shafts, switching contact(s)) of the switching device depend on the energy stored in the spring. For example, the spring of the drive device according to the invention can be used as so-called “Switch-off spring”, which thus drives at least one switching contact of an associated switching device in the sense of a switch-off operation. Applying the invention—without having to open the housing of the drive device which usually contains insulating gas—advantageously the switching time can be changed, as a result of which, for example, production tolerances of the springs and other components, age-related drift effects and the like can be compensated in a simple manner. In the case of switching systems with several switching devices and accordingly, several drive devices, which are respectively associated to the individual switching devices, the switching times of all switching devices can be adjusted by means of the adjustment options provided according to the invention, such that, for example, three-phase or multi-phase high-voltage power switches can be provided which have no appreciable deviations in the switching times between the respective phases.
In an embodiment, the housing has an opening, wherein an adjustment element, which can be coupled to the stop, of the adjustment device is arranged movably in the opening, in particular parallel to or along the axis.
In an embodiment, the housing has a guide for the adjustment element in the area of the opening. Particularly preferably, the housing has an internal thread in the area of the opening, wherein the adjustment element has an external thread cooperating with said internal thread. In this way, by screwing the adjustment element in the housing or by unscrewing the adjustment element from the housing the position of the stop serving for the tensioning of the spring and thus the mechanical energy which can be stored in the spring can be varied.
In an embodiment, a sealing element is provided which seals an interior space of the housing against the opening, wherein preferably at least one ring seal and/or one lip seal ring is associated with the sealing element. Alternatively or in addition to the sealing element, in further embodiments, the guide of the adjustment element or the thread of the adjustment element can be configured in such a way that it will have a sealing effect.
In a further embodiment, it is provided that the stop is arranged on an end face of the sealing element facing the interior space, whereby a particularly small-sized configuration is obtained.
In a further embodiment it is provided that the sealing element can be coupled to the adjustment element on its end face facing away from the interior. In a variant, the coupling of the elements can be formed in such a way that (only) compressive forces can be transmitted, assuming that the spring is exerting corresponding compressive forces on the sealing element and thus presses the latter against the adjustment element. In particular, it can also be provided that the sealing element and the adjustment element are not connected to one another in a rotationally fixed manner, so that a rotation thereof resulting possibly during a screwing operation of the adjustment element does not transfer to the sealing element and/or the spring. In particular, this also ensures that a possibly present ring seal is not subjected to rotation.
In a further embodiment it is provided that the sealing element is formed integrally with the adjustment element, as a result of which there is less installation effort.
A particularly simple adjustment of the position of the stop for the spring and thus of the storable energy is obtained according to a further embodiment in which the adjustment element has, on its side facing away from the interior space of the housing, a driving profile, for example a hexagon socket profile or the like.
In a further embodiment it is provided that the housing has a hollow cylindrical section, wherein the adjustment device and/or at least a part of the spring is arranged in the hollow cylindrical section, whereby the drive device is particularly small and possibly no further devices for guiding the spring in the housing are required. Furthermore, the housing in the area of the hollow cylindrical portion can be adapted to the geometry of the spring, thereby making it smaller in this area, for example, than other areas of the housing thus providing further degrees of freedom with respect to the arrangement of the drive device in or on a target system, in particular a high-voltage circuit breaker or a switching system.
In a further embodiment, it is provided that a ratio of an outer diameter of the hollow cylindrical section to an outer diameter of the spring is between about 110 percent and about 200 percent, in particular between about 110 percent and about 150 percent, resulting in a particularly small-sized configuration.
In a further embodiment it is provided that the spring at its end section facing away from said stop is coupled to a first lever arm of a lever rotatably mounted in the housing, in particular by means of a spring plate which is arranged rotatably on said lever. By means of the lever, the spring force can advantageously be transferred to another element of the chain of action of the drive device or the switching device associated therewith.
In a further embodiment it is provided that second lever arm of the lever is coupled to a drive rod for actuating a switching contact of said switching device.
In a further embodiment a secondary sealing element is provided which seals the interior space of the housing against the opening, in particular independently of the sealing element or independently of a state of the sealing element. The secondary sealing element can advantageously be arranged “in series” with the above-mentioned (primary) sealing element and further improve the sealing effect in the area of the opening.
In a further embodiment, a securing element is provided, which is configured for locking said adjustment device, in particular for locking a component of the adjustment device. In this way, an unintentional adjustment of the adjustment device is avoided, as may occur by vibrations and/or temperature changes.
As a further solution to the object of the present invention there is provided a switching system having at least one switching device and at least one drive device according to the invention.
Further features, possible applications and advantages of the invention will become apparent from the description of exemplary embodiments of the invention which are illustrated in the figures of the drawings. All the described or illustrated features form the subject matter of the invention either by themselves or in any combination, independently of their combination in the claims or their referral back and independent of their wording or representation in the description or in the drawing.
FIG. 1 shows schematically a first embodiment of the drive device 100 according to the invention. Drive device 100 is provided, for example, for driving a switching contact (not shown) of an electrical switching device 10, in particular for a high-voltage switch or a high-voltage circuit breaker, and in an embodiment, for example, can be arranged in a common housing 102 together with switching device 10. An interior space of housing 102 can be filled with an insulating fluid, in particular insulating gas, for example with SF6 (sulfur hexafluoride) and/or CF4 (tetrafluoromethane) and/or CO2 (carbon dioxide) and/or a gas from the group of fluorinated nitriles or mixtures thereof. A particularly preferred insulating fluid is, for example, a mixture of a fluorinated nitrile, which is marketed under the trade name Novec 4710 by the company 3M, with carbon dioxide. Such a mixture is also referred to as “G3” insulating gas.
In a manner known per se, drive device 100 has an energy storage device 12 which stores mechanical energy by means of at least one spring (not shown in FIG. 1) in a tensioned state of the spring.
According to the invention, an adjustment device 114 which can be actuated from the exterior of housing 102 is provided (not shown), by means of which a position of a stop (not shown), against which the spring is tensioned, can be adjusted in the housing along an axis. This allows the level of mechanical energy which can be stored in the spring of the energy storage device 12 and which can be retrieved for switching operations can be simply adjusted from the exterior on drive device 100 without having to open it.
FIG. 2a shows schematically a partial cross-section of a second embodiment 100a of the drive device according to the invention. As already described with reference to FIG. 1, drive device 100a, together with the switching device associated with it, of which only a drive rod 104 is shown in FIG. 2a, can be arranged in common housing 102. The interior space I of housing 102 can be filled with an insulating fluid, in particular with an insulating gas such as, e.g., SF6.
In housing 102, a lever 106 is provided, which is rotatably supported on a first shaft 106a and has two lever arms 106b, 106c. Lever 106 is used to transmit the spring force of spring 108, which is also arranged in housing 102, to drive rod 104 which, for example, affects a switching contact which is not shown of the switching device associated with drive device 100a. For example, spring 108 can be used as a so-called “Switch-off spring”, which—starting from a state tensioned against stop 112a—drives at least one switching contact of the associated switching device in the sense of a switch-off operation via lever 106 and drive rod 104.
In an embodiment, shaft 106a can also be routed to the exterior (not shown) through a housing wall so that torque can be applied to shaft 106a from the exterior by further drive components, such as, for example, an electromechanical drive or the like, in order to tension spring 108 (again).
In its end section 108a facing lever 106, spring 108 abuts against spring plate 110, as shown in FIG. 2a, which, preferably rotatably, is connected to lever arm 106b on the left in FIG. 2a. As already described, the other end of spring 108 abuts against stop 112a in a tensioned manner, which is part of adjustment device 114 according to the invention.
Adjustment device 114 has a substantially disc-shaped adjustment element 114a, which is movably arranged in an opening 102a of housing 102 along an axis running vertically in FIG. 2a, which in the present case corresponds to the longitudinal axis LA1 of spring 108. Adjustment element 114a has an external thread which cooperates with an internal thread 114b of housing 102 in such a way that adjustment element 114a can be screwed in the housing or unscrewed from the housing by rotation about axis LA1 resulting in the axial mobility indicated by block arrow P1. For this purpose, a driving profile, e.g., a common hexagon socket profile or the like may be provided on an exterior end face, i.e. at the bottom in FIG. 2a, of adjustment element 114a. 
Since opening 102a of housing 102 in the present case is arranged in a hollow cylindrical portion 102b of the housing, this portion 102b can advantageously simultaneously at least accommodate and/or guide a part of spring 108 and parts of adjustment device 114.
The adjustment element 114a is preferably coupled with a sealing element 112, wherein an interior end face of sealing element 112 advantageously has or forms stop 112a for spring 108.
The coupling of sealing element 112 with adjustment device 114 results in axial mobility of components 112, 114 and thus also stop 112a, against which spring 108 can be tensioned, so that the spring path of spring 108 and thus also the level of mechanical energy which can be stored in spring 108 by the tensioning of spring 108, can be adjusted in a simple manner by screwing in or unscrewing the adjustment element. As a result, by actuating the adjustment element 114a alone from the exterior, i.e., without opening housing 102, manufacturing-related tolerances and/or age-related or temperature-related changes in the spring constant of spring 108 can be compensated, so that precise maintenance of the required switching times of the switching device driven by drive device 100a is ensured by simple and cost-effective adjustment of the position of stop 112a throughout the life of the device. In particular, gas exchanges of the insulating gas and, in any case, opening/closing of housing 102 can be advantageously avoided.
In the operating state shown in FIG. 2a, a contact surface of stop 112a abuts against spatial coordinate x0 of the coordinate axis x pointing vertically downwards in FIG. 2a. In the operating state shown in FIG. 2b the contact surface of stop 112a abuts against spatial coordinate x1>x0 of the coordinate axis x, which corresponds to a lower energy which can be stored in spring 108.
In a further embodiment, an end face 112b (FIG. 2a) of sealing element 112 facing adjustment element 114a is detachably or non-detachably connected to the opposing surface of adjustment element 114a. 
In a further embodiment, the sealing element 112 has at least one circumferential groove, not indicated, in which a ring seal 112c is inserted, which seals the interior space I against the surroundings or opening 102a. Alternatively or in addition, a shell surface of sealing element 112 and the inner surface of the hollow cylindrical housing portion 102b facing the shell surface radially outwardly, can have a high surface quality, in particular low roughness, which can also contribute to the sealing effect. Alternatively or in addition to sealing element 112, in further embodiments, the guide of adjustment element 114 or thread 114b of the adjustment element can be configured to have a sealing effect.
In a further embodiment, it is provided that a ratio of an outer diameter d1 (FIG. 2b) of the hollow cylindrical portion to an outer diameter d2 of spring 108 is between about 110 percent and about 200 percent, in particular between about 110 percent and about 150 percent, resulting in a particularly small building configuration.
FIG. 3 schematically shows a three-phase switching system 200 according to an embodiment. Switching system 200 has a switching device 10a, 10b, 10c for each phase, which, in each case, is associated with a drive device 100a, 100b, 100c according to the invention. The drive devices 100b, 100c are advantageously configured in the same way as drive device 100a described with reference to FIGS. 2a, 2b. 
Advantageously, the switching times of all three switching devices 10a, 10b, 10c can be adjusted by the adjustment options for the position of stop 112a (FIG. 2a) provided according to the invention, so that no appreciable differences in the switching times occur between the respective phases.
In a further embodiment (not shown), spring 108 can also be configured as a tension spring and, for example, can also be arranged on second lever arm 106c with its first end 108a with respect to drive rod 104 (FIG. 2a). In this case, the second spring end can be attached to an adjustment element or a corresponding adjustment device configured for connection to the tension spring. Thus, in this embodiment, the first lever arm 106b can be omitted and a part of housing 102 which is comparable to portion 102b, e.g., in FIG. 2a below the mounting point of drive rod 104, can be arranged on lever arm 106c. In this case, the pulling force obtainable by the spring would be equally simply adjustable from the exterior by means of the adjustment device as the pretension at exemplary embodiment of FIGS. 2a, 2b. 
FIG. 4a shows schematically an aspect of a further embodiment 100b′ of the drive device according to the invention. For the sake of clarity, only the part of housing 102 is depicted which accommodates adjustment device 114. In addition to adjustment device 114 and (primary) sealing element 112, see also FIG. 2a, a secondary sealing element 1120 is provided in drive device 100b′ according to FIG. 4a, which seals the interior space I of housing 102 against opening 102a (FIG. 2a), in particular independently of the primary sealing element 112 and/or independently of any state of primary sealing element 112. In the present case, secondary sealing element 1120 is provided with an external thread which cooperates with the internal thread 114b of portion 102b, so that the secondary sealing element 1120 can be screwed into or out of housing 102. The secondary sealing element 1120 in this case has, in its lower area in FIG. 4a, a flange-like widening which carries a second seal ring 1122, which, upon screwing the secondary sealing element 1120 into the housing 102 is pressed against housing 102 and thus contributes to the sealing of interior space I. This results in an in-series connection of the two sealing elements 112, 1120 between interior space I and the surroundings. Overall, the secondary sealing element 1120 has, for example, a substantially T-shaped cross-section.
In a further embodiment, the secondary sealing element 1120 can also have a stuffing box.
In a further embodiment, housing portion 102b can also have, for example, a flange (not shown) in its lower area in FIG. 4a, on which a sealing ring comparable to component 1122 is arranged. In this case, the secondary sealing element can be formed, for example, by a substantially disc-shaped body which can be attached to the flange (in particular can be screwed on or clamped) and in this way is held sealingly against seal ring 1122 relative to housing 102.
FIG. 4b schematically shows an aspect of a further embodiment 100c′ of drive device according to the invention. Again, for the sake of clarity, only the part of housing 102 is depicted, which accommodates adjustment device 114. Here a securing element 116 is provided, which is configured for locking adjustment device 114, whereby undesirable adjustment of adjustment device 114 is avoided, as may occur, for example, by vibrations and/or temperature changes. In the present case, securing element 116 is configured as a counter screw with an outer thread (not shown) matching the inner thread 114b and can be screwed tight by screwing it into the housing portion 102b against adjustment device 114 for locking adjustment device 114. FIG. 4b shows a state in which the counter screw 116 does not already have contact with adjustment element 114a. 